DFM 5.1 Doppler Flow Meter

  • Easy Mounting, Single Head Sensor
    12.5mm up to 4500mm 
  • Wide Flow Rate
    Velocity: +/-0.003 - 12 m/s
  • PC Software
    Builtin Datalogger and retrieval software
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Measure flow from outside a pipe. The Greyline DFM 5.1 is designed for "difficult liquids" that would damage regular flow meters - wastewater, slurries, sludge, chemicals, viscous liquids and abrasives. There is no obstruction to flow and no pressure drop. The non-intrusive, clamp-on ultrasonic sensor fits any pipe 1/2" (12.5 mm) Inside Diameter or larger. The electronics/display enclosure can be mounted nearby.

Use the isolated 4-20mA to transmit flow to remote displays, recorders or controllers. The programmable relays can be used for flow control, pump protection or flow proportionate pulse. Calibration is easy with the built-in 5-key calibrator. Display and totalize flow in your choice of engineering units (gallons, liters etc.)

Sensor cable can be extended up to 500 ft. (152 m) with no loss of signal. The standard sensor is rated non-incentive for Class I, Division 2 hazardous locations and the DFM 5.1 can be equipped with optional Intrinsic Safety Barriers for sensor installation in Class I, Division I hazardous locations. Other options include extra control relays and a built-in 2 million point Data Logger with USB output to Flash Drives.

The DFM 5.1 includes a new digital signal processor to filter background noise and interference, and to measure flow rates accurately in liquids containing gas bubbles or solids particles.


General Specification
Transmitter Enclosure 


Operating temperature: -20°C to +150°C (High temperature optional: up to +200°C)

Isolated 0/4-20mA

Data Logging Built-in 2 million point logger with output and Windows™ software
Sensor Specification
Pipe diameters range:

12.5 up to 4500mm

Operating temperature: -20°C to +150°C (High temperature optional: up to +200°C)
Accuracy 2%





Viscous liquids